I would like to use “Pollocks Robust Design” for a CMR study of endangered arboreal snails and would like some feedback on my approach. 

Collection surveys will be 2 sets of day-night-day data collection with 3 weeks in between events.    Or would “better” data be collected with more visits? The snails are  sedentary during the day- easier to spot at night using lights while they are moving. So, we know we find more snails at night. Is it ok to mix up the time of day that the data collection occurs?  

Survey Area is about ½ acre of enclosed habitat but the snails are concentrated in hotspots within this area. Should I survey those hotspots to get the maximum number of individuals or should I choose random quadrats within the ½ acre with the chance that the quad will have no snails. If quadrats then how many? I am planning to do a timed collection (one man hour for each area) but should I search to exhaustion in each section instead? One of my goals is to determine the approximate number of snails in this enclosed area but much of the habitat is too tall to be searched

I am planning to use Program MARK for the data analysis- any guidance regarding doing Robust Design analysis is welcome. I have worked my way through MARK before for closed capture CMR.

Thank you for any feedback.